CFD技术在海洋平台可燃气体泄漏模拟中的应用

计算流体动力学(CFD)技术可以实现分析、判断和预测天然气泄漏后所影响到的扩散区域,对事故的预防、控制以及平台应急、逃生方面具有指导意义。文章介绍了CFD方法以及可燃气体泄漏的相关理论,并对海洋平台可燃气体泄漏进行模拟分析,研究结果可为泄漏现场人员疏散和安全技术管理提供有效依据。     

核潜艇内空气龄的计算方法探讨

介绍空气龄的两种计算方法及其基本原理，比较了示踪气体测试法和CFD方法的适用范围及优缺点，考虑到核潜艇特殊密闭空间的空气品质的重要性，针对核潜艇的特殊情况，提出了计算空气龄的方法。     

基于Daubechies4小波变换地形滤波的复杂电磁环境仿真加速方法

本文提出了一种基于射线追踪算法的复杂电磁环境仿真计算的加速方法,同时结合并行系统来共同加速仿真计算。对地形DEM数据进行Daubechies4二维离散小波变换,地形滤波在一定范围内有效降低了其复杂度。继而搭建并行计算系统,将滤波后的地形应用到多个辐射源的仿真建模并行计算,提高复杂电磁环境仿真计算速度。经过对该方法进行多次实验,验证了该方法可以在一定精度范围内提高复杂电磁环境计算速度。     

计算流体动力学在模拟气升式环流反应器中的研究进展

计算流体动力学(CFD)是对气升式环流反应器进行数值模拟的重要手段.为此,本文综述了CFD模拟概况及气升环流反应器中流体数值模拟研究进展,总结了目前CFD模拟气升环流反应器存在的问题,并提出了进一步的研究方向.     

基于GIS修正法与因素法的农用地定级研究——以四川省乐山市中区为例

以GIS为平台，采用修正法和因素法相结合，对乐山市中区农用地定级进行了研究。通过确定因素权重、选择定级模型，计算出修正法和因素法两种定级结果。经过实地验证和模型模拟分析表明：修正法比因素法更适合县级农用地定级，同时修正法能与农用地分等成果相衔接，比因素法适用效果更好。采用GIS技术，实现了系统、快速、科学的农用地定级，对其它地区开展农用地定级工作有很好的借鉴作用。     

雷达关键部件对西北地区典型环境适应性的综合仿真研究

长期工作在西北地区大温差、多风砂和强紫外线等恶劣复杂环境下的雷达装备表面极易出现表面磨蚀或损坏。建立了雷达对西北地区综合环境适应性的仿真分析方法,以计算流体动力学(CFD)软件FLUENT为平台,对雷达典型部件在大温差、多风砂和强紫外线环境中的表面状态进行仿真模拟。仿真结果与雷达装备实际情况较为吻合,为进一步深入研究相关物理机理以及设计防护措施提供了理论依据。     

室内空气品质评价

介绍国内外有关室内空气品质的评价方法，着重介绍CFD和多区域两类模拟方法。     

CEMS检测平台流场效应研究与工程设计

本研究项目设计了小型立式环型风洞系统和流场模拟两套实验装置。用工程流体力学实验的方法，对系统内气体压力、流量变化的调节控制方法、通风机的能量消耗，以及在检测平台系统工作段形成均匀流动流场的设计方法等工程实际问题，进行了一系列的试验研究。在试验研究的基础上确定了检测平台系统的设计方案。     

袋除尘滤料过滤性能测试平台改造研究

过滤性能是袋除尘滤料的核心指标,其测试对评估滤料性能、保证滤料质量相当重要.本文在分析现有测试标准的基础上,对既有的测试平台进行了改造,改造后不仅拓宽了既有平台的适应范围,而且极大节省了成本.本研究对滤料生产与质量评定有积极意义.     

除尘器入口烟道流场流动力学数值模拟技术

结合燃煤电厂电袋复合除尘器的入口烟道气流分布的工程案例,采用计算流体动力学（简称CFD）数值模拟技术,对烟道内的速度场进行三维数值模拟;根据分析结果进行烟道的导流板的设置,改善烟道的流场,并使入口烟道的各分支烟道流量分配均匀。对比现场烟道流量分配的测试结果,验证了CFD模拟计算的准确性。     

并联三自由度运动平台动力学分析

本文由三自由度并联机构的结构入手,介绍了一种一平移两转动的三自由度运动模拟平台,此平台通过改变三个可伸缩的支撑杆的长度来实现模拟平台的特定位姿。应用拉格朗日方程建立动力学模型,分析了机构的结构参数与驱动力的关系,为机械结构设计提供了依据。     

Numerical simulation of chemical looping combustion process with CaSO4 oxygen carrier

Chemical-looping combustion (CLC) is a promising technology for the combustion of gas or solid fuel with efficient use of energy and inherent separation of CO₂. The technique involves the use of an oxygen carrier which transfers oxygen from combustion air to the fuel, and hence a direct contact between air and fuel is avoided. A chemical-looping combustion system consists of a fuel reactor and an air reactor. A metal oxide is used as oxygen carrier that circulates between the two reactors. The air reactor is a high velocity fluidized bed where the oxygen carrier particles are transported together with the air stream to the top of the air reactor, where they are then transferred to the fuel reactor using a cyclone. The fuel reactor is a bubbling fluidized bed reactor where oxygen carrier particles react with hydrocarbon fuel and get reduced. The reduced oxygen carrier particles are transported back to the air reactor where they react with oxygen in the air and are oxidized back to metal oxide. The exhaust from the fuel reactor mainly consists of CO₂ and water vapor. After condensation of the water in the exit gas from the fuel reactor, the remaining CO₂ gas is compressed and cooled to yield liquid CO₂, which can be disposed of in various ways.With the improvement of numerical methods and more advanced hardware technology, the time needed to run CFD (Computational fluid dynamics) codes is decreasing. Hence multiphase CFD-based models for dealing with complex gas-solid hydrodynamics and chemical reactions are becoming more accessible. Until now there were a few literatures about mathematical modeling of chemical-looping combustion using CFD approach. In this work, the reaction kinetics model of the fuel reactor (CaSO₄ + H₂) was developed by means of the commercial code FLUENT. The bubble formation and the relation between bubble formation and molar fraction of products in gas phase were well captured by CFD simulation. Computational results from the simulation also showed low fuel conversion rate. The conversion of H₂ was about 34% partially due to fast, large bubbles rising through the reactor, low bed temperature and large particles diameter.     

NO70燃烧系统在燃煤锅炉脱硝中的应用

介绍了NO70燃烧系统的特点以及计算机流体力学模拟原理。分析了使用NO70燃烧系统技术对旺隆电厂的2×100MW四角切圆燃煤锅炉进行改造,有效降低氮氧化物排放量并提高机组效率的案例。     

基于Silverlight的主要污染物排放总量重点控制区地理信息系统设计与实现

主要污染物排放总量重点控制区地理信息系统的开发平台是基于Microsoft Visual Studio 2010,采用SuperMap IS.NET和Silverlight技术,为安全便捷生成和管理区域文本、图件、数据提供软件平台,主要实现重点控制区地理信息系统基本操作、专题图制作、空间属性查询、嵌入数字地球、网络信息发布等功能,为总量控制工作提供相关参考数据和独立运行平台。     

埕岛油田2号中心平台除砂工艺

介绍了中心平台油气处理工艺、清除采出砂的必要性和要求。论述了地面集输系统的除砂方法以及中心平台除砂工艺，评价了除砂方法和工艺的优、缺点。供海上油田作业时借鉴。     

西柏坡电广烟气脱硫装置的运行诊断及优化

以西柏坡电厂一期2×300MW烟气脱硫工程为例,对吸收塔运行状况进行运行监测及化学分析,在不进行大规模改造的前提下,通过CFD技术模拟不同工况下的吸收塔烟气流场,通过增加导流板优化吸收塔烟气流场的分布,达到了提高脱硫效率的目的,对已建成的吸收塔进行后期优化改造,有良好的借鉴作用.     

Investigations on Blade Tip Tilting for Hawt Rotor Blades Using CFD

The main purpose of this paper is to study the aerodynamic effects of blade tip tilting on power production of horizontal-axis wind turbines by using Computational Fluid Dynamics (CFD). For validation and as a baseline rotor, the NREL Phase VI wind turbine rotor blade is used. The Reynolds-Averaged Navier–Stokes Equations are solved and different turbulence models including the Spalart–Allmaras, Standard k-?, k-? Yang–Shih and SST k–ω models are used and tested. The results are shown in terms of power generation at different wind speeds and the pressure distribution at different sections of the blade, and the comparisons are made with the available experimental data. For tip tilting analysis, 16 different geometries belonging to four different configurations are studied. The geometries are generated based on changing the twist and the cant angles of the winglet. The four different configurations are obtained from tilting the blade tip toward pressure side, suction side, leading edge, and trailing edge. The effect of the different configurations on the flow characteristics and hence on the power production of the wind turbine is investigated.